The present invention relates to pallets of the type used to store and transport manufactured goods and more particularly, to pallets of this type constructed of paper materials.
Pallets have been widely used for stacking manufactured goods during storage in a manner which permits easy movement. In the past, the majority of pallets have been constructed of softwood. Of the available materials, softwood has provided the best balance of strength and cost. However, the cost of making and repairing wooden pallets is rising at a rate that is detracting from the cost effectiveness of palletized shipment. Moreover, empty wooden pallets require substantial space for storage, and transportation of empty pallets by rail or truck is especially costly.
There have been a variety of attempts over the years to replace wooden pallets with those constructed of paperboard. However, they were not as sturdy as wooden pallets and none has received widespread acceptance. In recent years attempts have been made to replace the bulky and expensive wooden pallets with paperboard sheets called slip sheets. These slip sheets simply comprise a sheet of corrugated paperboard which is slightly larger than the dimension of the goods to be stacked thereon. The slip sheet is neither intended for nor capable of supporting the weight of the stacked goods, and must always be supported on a suitable horizontal surface. By providing an extra marginal edge of corrugated board material, it is possible to grasp and slide the sheets and the goods carried thereon about the floor or onto a specially designed lift truck.
While slip sheets have provided considerable cost savings in many industrial situations, they are not suitable to fully replace palletized shipments in many others. For example, difficulties have been encountered where heavily loaded slip sheets are positioned directly adjacent the doorway of a fully loaded boxcar or truck trailer. When so positioned, the lift truck mechanism cannot grasp a sufficient portion of the slip sheet to pull it onto the lift truck. The slip sheets improperly grasped are often ripped. This has necessitated, in many situations, totally unloading the sheet to move the goods out of the carrier and then restacking the goods on the sheet for transport by lift truck.
In summary, the prior art has experienced considerable difficulties with both wooden pallets and their paperboard replacements in the past.